Crate sgx_panic_backtrace

sgx-panic-backtrace

A small library for printing out panics and backtraces inside an SGX enclave.

Why

• Get backtraces working while we wait for backtrace-rs to get fixed : )

Usage

Add sgx-panic-backtrace to your Cargo.toml:

[dependencies]
sgx-panic-backtrace = "0.1.0"

In the enclave, call sgx_panic_backtrace::set_panic_hook() in your main function:

sgx_panic_backtrace::set_panic_hook();

If the enclave panics (and panic=abort is not turned on!) it will now print out the raw backtrace frames to stdout. These include only the frame index and relative frame instruction pointer offset, which you’ll need to symbolize outside the enclave itself.

$ cargo run --target=x86_64-fortanix-unknown-sgx

enclave: panicked at 'foo', bar.rs:10:5
stack backtrace:
   0: 0x1b09d9
   1: 0x1396f6
   2: 0x10f4cc
   3: 0x48b3ef
   4: 0x2d540b
   5: 0x2d56fa
   6: 0x2d531d
   7: 0x16c681
   8: 0x116fd0
   9: 0x13410e

To get human readable symbol names and locations from these raw ips, you may wish to use the stack-trace-resolve utility that comes with the Fortanix EDP.

For example:

$ ftxsgx-runner <my-enclave-bin>.sgxs | stack-trace-resolve <my-enclave-bin>

Functions

set_panic_hook

Set a panic hook that will print out the panic and raw backtrace addresses when the enclave panics. These addresses will need to be symbolized to human- readable symbol names and locations outside the enclave with a tool like addr2line.